Control of undesirable plant growth



United States Patent 3,183,074 CONTROL OF UNDESIRABLE PLANT GROWTH Bryant L. Walworth, Pennington, and Albert W. Lutz and Kathryn Wood, Princeton, NJ., assignors to American Cyanamld Company, Stamford, Conn., a corporation of Maine No Drawing. Filed May 31, 1962, Ser. No. 198,773 1 Claim. (Cl. 71-25) The present invention relates to herbicidal compositions. More particularly, it relates to herbicidal compositions containing as an active ingredient a mono-epoxy compound represented by the formula:

(X)m wherein R is hydrogen, lower alkyl or lower alkoxy, X is a halogen, such as fluorine, chlorine, bromine or iodine, and m is an integer from 0 to 3.

Illustrative of the mono-epoxy compounds which can be employed in the present invention are:

1- (phenoxy -2,3-epoxypropane;

1- (Z-fluorophenoxy -2,3-epoxypropane;

1- (2-chlorophenoxy -2,3-epoxypropane;

1- (4-chlorophenoxy) -2,3-epoxypropane;

1- (2-allylphenoxy) -2,3-epoxypropane; l-(2,4-dichlorophenoxy) -2,3-epoxypropane;

1- 3,4-dichlorophenoxy) -2,3-epoxypropane;

1- (2,4,5 -trichlorophenoxy) -2,3-epoxypropane;

1- (Z-methoxyphenoxy) -2,3-epoxypropane; 1-(2-ethoxyphenoxy) -2,3-epoxypropane;

1- (4-chloro-2-methoxyphenoxy) -2,3-epoxypropane; 1- 2-methyl-4-chlorophenoxy -2,3 -epoxypropane; 1- 3 ,5-dimethy1-4-chlorophenoxy) -2,3-epoxypropane', 1- (p-bromophenoxy) -2,3-epoxypropane; 1-(2,4,6-triiodophenoxy -2,3-epoxypropane;

1- (2,4,6-tribromophenoxy -2,3-epoxypropane.

Each of the mono-epoxy compounds employed in the compositions of the present invention can be prepared according to any desired procedure known in the art as illustrated for instance in U.S. Letters Patent No. 2,221,771.

In general, the herbicidal compositions of the present invention are prepared by admixing the active compound with an inert carrier material of the type or kind referred to in the art as pest control adjuvants in solid or liquid form. Typical carriers include the tales, clays, pumice, silica, chalk, diatomaceous earth, walnut shell flour and equivalents thereof.

Liquid compositions may be prepared by dissolving the active compound in water or by initially dissolving in common organic solvents and then admixing the resultant solutions with water either with or without an emulsifying agent. Mono-epoxy compounds are quite soluble in common organic solvents, such as acetone, methyl isobutyl ketone, ethanol, dioxane and isopropyl acetate.

Emulsifying or surface-active agents which can be employed herein, are those normally employed for the preparation of oil-in-water emulsions. Illustrative of the latter are ionic and non-ionic dispersing or emulsifying agents, such as the higher alkylaryl sulfonates or polyglycol ether, which are commercially available. The emulsifying agent is generally employed in small concentrations in the range of from about 0.1% to 2% by weight of the total weight of the composition.

The compounds of the present invention may be applied either as a spray or as a dust to the area or locus to be protected from undesirable plant growth. The

3,183,074 Patented May 11, 1965 amount of the mono-epoxy compound in the herbicidal composition will, of course, vary in the manner and purpose for which the composition is to be employed. Concentrates for subsequent use in preparing spray formulations may contain as much as or more, by weight of the active ingredient. Sprays or dusts for direct use will be relatively dilute, in some cases as low as 0.5% or less.

The invention will be further illustrated by the following examples. These are not to be taken as limitative of the invention. Unless otherwise noted, the parts are by weight.

EXAMPLE 1 The herbicidal activity of the mono-epoxy compounds employed as test compounds is illustrated using a seed germination technique.

Wheat and radish seeds are placed in an aqueous solution of the test compound at 1000 parts per million. These are agitated continuously for twenty-four hours. After this exposure period, the seeds are removed from contact with the test compound, placed in a germination cabinet and the percent germination plus any observation regarding growth are recorded after five to six days. Seeds exposed to distilled water alone are included as controls. The results of this test are recorded in Table I below on the scale of 0% to where 100% indicates normal germination and 0% indicates no germination.

' Table 1 Percent Germination Test Compound Wheat Radish F t- 30o QOGOOwQOO pane 1-(2-methoxyphenoxy)-2.3-epoxypropane I-(B-methoxyphenoxy)-2,3-epoxypropane 1-(Mnethoxyphenoxy)-2,3-epoxypropane Distilled water control 82 00: DCODQQOOO flSgeds germinated but both wheat and radish had physiological growth e ec s.

EXAMPLE 2 This example illustrates the compounds of the present invention as contact herbicides. Such herbicides when applied to growing plants will kill or control the growth of all plants in the treated area. Alternatively, selected compounds may be used to kill or control undesirable plants with no signigcant effect on desirable plants, demonstrating their selective activity.

Established, vigorously growing seedlings of pea, radish and tomato are used as representative of dicotyledonous plants and wheat as representative of monocotyledonous plants. Test compounds are applied in solution (75% acetone and 25% water, by volume) at a rate equal to 12.5 pounds per acre. To the latter solution is added 0.2 part of dodecylbenzene sodium sulfonate based on the weight of the total composition. The effects on plant growth are recorded fourteen days after application.

In the data represented in Table II below, a 0 to 5 rating system is employed. The zero (0) designation means no etfect and the five (5) designation means complete kill.

=No observed etiect.

t 1+ =Traee injury.

1= Slight injury.

2 Moderate injury.

3 :Severe injury, but no kill.

4 evere injury and 75% or less of the plants lrllled. 4+-Severe injury and 75-90% of the plants killed. 5 -90-99% of the plants killed.

5 :All of the plants killed.

EXAMPLE 3 To evaluate the mono-epoxy compounds of the present invention as pre-emergence herbicides, wheat and radish seeds are planted in unsterilized potted soil and the test compound is applied to the soil surface at the rate of twenty-five pounds per acre. Data are recorded fourteen days after application. The effects on plant growth are recorded in Table III below according to the system employed in Table II.

Table III Herbitoxic Index, 25 lbs/acre Test Compound Wheat Radish 1-(3-chlorophenoxy)-2,3-epoxypropane 3 5 1-(4-ehlorophenoxy)-2,3-epoxypr0pane. 2 5 1-(4-brom0phenoxy)-2,3epoxypropane 3+ 5 1-(2,4-diehlorophenoxy)-2,3-epoxypropane 4 5 1-(2,4,Mrichlorophenoxy)-2,3 epoxypropane 1 5- 1-(3-ethylphenoxy)-2,3-epoxypropane 0 4+ l-(2-methyl-4-ehlorophenoxy)-2,3-epoxypropane 5 5 "Ilerbitoxic Index: For definition see Table II above.

EXAMPLE 4 This example illustrates the outstanding selective herbicidal effectiveness of the compounds of this invention. Two compounds, (I) 1-(4-ch1orophenoxy)-2,3- epoxypropane and (II) 1-(2-methyl-4-chlorophenoxy)- 2,3-epoxypropane, demonstrate this utility. Applications are made in the manner identical to Example 3 and data recorded as in Example 3.

Table IV Herbitoxlc Index Compound I, Compound II, Test llnnt rate in rate in lbs/acre lbs/acre Herbitoxie Index: For definition see Table II above.

TIhe compound resulted in hormonal growth efiects.

The mono-epoxy compounds of the present invention can be admixed advantageously with other active ingredients, such as for instance, fungicides, insecticides, fertilizers and hormones to produce multi-purpose formulations. The latter may be either in the form of powder or liquid.

We claim:

A method for the control of undesirable plant growth which comprises: applying to an area to be protected from such growth, 1-(2,4-dichlorophenoxy)-2,3-epoxypropane in an amount sutficient to effect herbicidal action.

References Cited by the Examiner UNITED STATES PATENTS 2,221,771 11/40 Alquist et a] 260348 2,221,818 11/40 Slagh et a1. 260348 2,434,099 1/48 Bousquet 260-348 2,577,969 12/51 Jones 712.6 2,986,569 5/61 Monroe et a1. 71-2.5 X 2,986,570 5/61 Monroe et a1 712.5 X 2,993,058 7/61 Hudson 7l-2.5 X

OTHER REFERENCES Thompson et al.: BotanicalGazette, volume 107, pages 475-507 (pages 489, 490 and 500).

JULIAN S. LEVITT, Primary Examiner.

G. D. Mitchell, Examiner. 

